F5CAB4 Control Plane Administration Practice Question
An administrator is troubleshooting an issue where changes made through the BIG-IP Configuration utility (GUI) are not appearing in the tmsh configuration. The administrator suspects that the GUI and tmsh are using different configuration sources. Which statement correctly describes how the GUI and tmsh interact with the BIG-IP configuration?
⚠ Common exam trap
The trap here is assuming that the GUI and tmsh use separate configuration stores or that direct file editing is equivalent, when in fact they both rely on mcpd.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Both the GUI and tmsh modify the configuration through the mcpd daemon, which updates the configuration files.
The GUI and tmsh are both front-ends to the same configuration management system, centered on the mcpd daemon. When a change is made in either interface, it is sent to mcpd, which updates the in-memory configuration and eventually writes it to the configuration files. This design ensures that changes made in one interface are reflected in the other, provided they are saved.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
The GUI uses a proprietary protocol to communicate with the configuration, while tmsh uses SNMP.
Why it's wrong here
The GUI does not use a proprietary protocol; it uses HTTPS to communicate with the web server, which then interacts with mcpd. tmsh does not use SNMP for configuration; it uses a local socket to communicate with mcpd. SNMP is used for monitoring and some management, but not for configuration changes via tmsh.
- ✓
Both the GUI and tmsh modify the configuration through the mcpd daemon, which updates the configuration files.
Why this is correct
The GUI and tmsh both communicate with the mcpd (Master Control Program daemon) to make configuration changes. The mcpd daemon is responsible for managing the configuration database and writing changes to the appropriate configuration files, such as /config/bigip.conf. This ensures consistency between the GUI and tmsh. Therefore, changes made in the GUI should be visible in tmsh after they are committed.
- ✗
The GUI writes directly to the bigip.conf file, while tmsh reads from a separate database.
Why it's wrong here
The GUI does not write directly to the bigip.conf file. Both the GUI and tmsh interact with the configuration through the mcpd daemon, which manages the configuration database. Direct file editing is discouraged and can lead to inconsistencies. The GUI and tmsh both use the same underlying configuration system.
- ✗
tmsh reads the configuration from the bigip.conf file every time a command is entered, while the GUI caches settings in memory.
Why it's wrong here
tmsh does not read the bigip.conf file for every command. It interacts with the mcpd daemon, which holds the current configuration in memory and writes to disk when changes are saved. The GUI also interacts with mcpd and does not simply cache settings independently. Both interfaces rely on mcpd for the authoritative configuration state.
About these practice questions
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JA
Written and reviewed by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
Last reviewed September 2026 · checked against the official F5 exam blueprint
This F5CAB4 practice question is part of Courseiva's free F5 certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the F5CAB4 exam.